Method of securing devices to shafts



June 23, 1942.

QKDUDA Filed April 8, 1938 Oswald. Duda- MEW- Patented June 23, 1942METHOD OF SECURING DEVICES TO SHAFTS Oswald Duds, Corsicana, Ten,assignor toAmer- I icanWell & Prospecting Company, a corporatlonApplication April 8, 1938, Serial No. 200,974

1 Claim.

- The invention relates to sprocket wheels, drum heads and the like andpertains particularly to the method of mounting such devices in positionfixed upon the shaft. The usual method of securing the hub of a sprocketwheel or the like upon a shaft includes boring the hub of the wheelslightly larger than the shaft, sliding the hub over the shaft to thedesired position and then fixing the wheel in position by means of atapered key driven within opposed keyways in the shaft and hub. This isgenerally unsatisfactory because the key will rarely remain tight andwhen it does stay tight the wheel rusts upon the shaft so that it ishard to remove. 1

It is an object of the method of this invention to so construct the hubof the wheel or drum head that it may be expanded to fit upon the shaftand after it is in proper position to then tighten the hub upon theshaft and key so that it will be 'flxedrigidly and yet be capable ofexpansion for removal without difliculty.

I aim toprovide a method in which a hub may be expanded and bored to aninternal diameter slightly greater than the outer diameter of the shaftso that it can be easily moved along the shaft to proper position andthen released to fit the shaft tightly. I

I have as another object the provision of a method using simple andeasily operated means of expanding the hub temporarily, said means alsoacting as a means of tightening the hub upon the shaft when said hub hasbeen positioned thereon.

Referring to the drawing herewith,

' Fig. 1 is an end view of a sprocket wheel having a hub thereon formedin accordance with my invention.

Fig. 2 is a vertical section thereof on the plane 2--2 of Fig. l.

Fig. 3 is a broken view of the split portion of the hub showing the hubtightened in position on the shaft.

diameter of the interior 1v of which is oriSlnally less than theexternal diameter of the shaft. In order that the hub be mounted on theshaft, I arrange to expand the hub so that it may be fitted over theshaft. On one side of the hub is formed a keyway I, which is adapted tocoop-- ing ears 6 and l on the hub, one on each side of the division inthe hub. The car i is formed with a threaded opening 8 therein toreceive a threaded bolt 9-. The opposite ear is formed with an openingl0 therein, which is-unthreaded. I

Fig. 4 is an end view'of a drum head having a device includessprocketwheels, drum heads,

clutches, and the like, and in the present disclosure I have illustratedit as applied to sprocket wheels and drum heads.

In Figs. 1 to a, inclusive, 1 have shown a sprocket wheel I, having ahub 2 thereon, the

form a plate ll of steel or hard material which can be inserted into thesplit portion 5 and engage over the opening l0, so that when the bolt '9is screwed inwardly it will engage against the removable plate ll.Screwing the bolt up tightly the hub will spread apart severalthousandths of an inch so as to slightly enlarge the central bore 3 ofthe hub.

I then bore the interior 3 of the hub to a size about .002 of an inchoversize, so that it may engage the shaft loosely.

With the hubv expanded outwardly it may he slid freely over the shaft,the keyway A engaging over the key 25 in the shaft. When the properposition upon the shaft has beenreached the bolt 9 can be unscrewed torelease the plate it and when the bolt has been thus unscrewed the hubwill automatically contract to it normal size, thus contacting with .theshaft tightly so bolt when tightened will clamp the two ears together,as shown in Fig. 3. The nut l2 may be screwed upon the end of the boltto lock it against unscrew As will be no d thisis a very simple operation. The bolt I.- when in the position shown in F a. 1, will notinterfere with the operation of fitting the sprocket wheelover the shaftand into Proper Position, and when this position is reached it is a,very simple operation to unscrew the bolt sufllciently to release theplate II and then to further tighten the hubinto position. When thusfixed, it'is so firmly set upon the shaft that junction with the plateII to expand the 'hub' and when thus expanded the hub may be easilyremoved from the shaft.

In Figs. 4 and 5 I have illustrated the invention as applied to the hubof a drum head I3. The drum head I3 is provided with a hub H which issplit on opposite sides and on each side of the split portion is formedears I5 and I6, and it will be understood that one of the opposing earson each side is threaded while the other is not, in the same manner aswas described relative to the sprocket wheel. The drum head has its hubsplit on opposite sides because of the heavier construction of both thehub and the drum head.

In the operation of mounting this hub upon the shaft the bolts 9 uponeach side arescrewed against the plates I l in the same manner as hasbeen described, thus spreading the hub. The hub is then bored slightlyoversize relative to the outer diameter of the shaft, so that it may beengaged over the shaft and when in proper position the hub may bereleased to engage the shaft tightly and. it may then be clamped inplace by the use of the bolts and nuts.

. It will be noted that in connection with the hub H of the drum headthere are two opposing keyways H, which when the hub has been contractedserve to prevent relative rotation of the hub upon the shaft after saidhub has been clamped rigidly thereto.

The operation of clamping the hub of the drum head upon the shaft is thesame as has been described relative to the sprocket wheel. In priorpractices it has been necessary without spreading to bore the openingthrough the hub of a diameter slightly larger than the shaft and tosecure it'in position upon the shaft by set screws. This has not beenentirely. satisfactory and the present method overcomes the diflicultieswhich have been previously experienced and make the mounting of the drumupon the shaft a very simple operation. The advantages of thisconstruction will be obvious to those skilled in the art.

' What is claimed is:

A method of fitting fastening and releasing sprocket wheel and the likehubs upon shafts which comprises providing a hub having a split thereinwith an extending ear at each side of the split, threading a member intoone ear and against the other ear to spread the ears and expand the hubwithin the elastic limit of the material, boring the hub to a size butslightly greater than the diameter of the shaft while the hub is

